The use of tooling composed of a puller (including a nosepiece), a mandrel and a split sleeve, for prestressing material surrounding holes in structural members is described, for example, in U.S. Pat. No. 4,471,643, granted Sep. 18, 1982 to Robert L. Champoux and Charles M. Copple. This patent discloses (FIG. 9) a preferred nosepiece having a conical end that fits inside the flare of a split sleeve and transfers the pull force directly through the periphery of the hole. This patent also discusses the need that sometimes exists for a pull gun nosepiece that is relatively long and narrow. An object of the present invention is to provide tooling having the functional capabilities of the tooling disclosed in U.S. Pat. No. 4,471,643 but also permitting an easy and relatively inexpensive length change of the nosepiece and mandrel assembly by use of a reduced inventory of parts.
It is also known to use a puller (including a nosepiece), a mandrel and a split sleeve in combination for installing tubular bushings or the like into openings in structural members. By way of example, see U.S. Pat. No. 5,103,548, granted Apr. 14, 1992 to Leonard F. Reid and Roger T. Bolstad. By way of another example, see U.S. Pat. No. 5,096,349, granted Mar. 17, 1992, to Michael A. Landy, Roger T. Bolstad, Charles M. Copple, Darryl E. Quincey, Eric T. Easterbrook, Leonard F. Reid, and Louis A. Champoux.
The aforementioned patents, the references cited against them, and a paper by Joseph L. Phillips, entitled "Fatigue Improvement By Sleeve Coldworking", should be carefully considered for the purpose of putting the present invention into proper perspective relative to the prior art.
Herein, the expression "split sleeve cold expansion" is used to describe the use of a split sleeve and mandrel for radially expanding a workpiece. The term "workpiece" is used to include both a structural member that is radially expanded about an opening for the purposes of fatigue enhancement and a tubular sleeve that is being installed in an opening in a workpiece by radial expansion.